Interest in poly(ethylene furanoate) (PEF) polyesters, also termed poly(ethylene-2,5-furandicarboxylate), as a potential replacement for poly(ethylene terephthalate) (PET) has increased in recent years, largely due to the ability to synthesize PEF from bio-based sources. Generally, the differences between the physical-chemical behavior of PEF versus PET has presented substantial challenges to the wholesale use of PEF in conventional PET-based applications. For example, compared to standard commercial grade poly(ethylene terephthalate), PEF polyesters often possess lower crystallinity, crystallize at slower rates, and are entangled to a lesser extent.
In order to develop a roadmap for increased use of PEF, particularly as a prospective PET replacement, it has been of interest to examine the differences in the fundamental materials and engineering aspects of PEF versus PET. In particular, a better understanding of the thermodynamic and kinetic differences between PEF and PET in their water sorption properties and other factors that affect plasticization would be useful.